Application Value Of ¹⁸F-FDG PET/CT In Small Pulmonary Nodules

Objective:Investigate the practicality of ¹⁸F-FDG PET/CT in small pulmonary nodules.Methods:A retrospective analysis of 139 patients with small pulmonary nodules who underwent surgical resection in the Department of Thoracic Surgery at China-Japan Union Hospital of Jilin University from January2022 to October 2022 was conducted,utilizing SPSS 26.0 for statistical analysis.The sensitivity,specificity,accuracy,positive predictive value and negative predictive value of ¹⁸F-FDG PET/CT in the diagnosis of small pulmonary nodules were calculated and the clinical factors which influence the consistency of ¹⁸F-FDG PET/CT diagnosis and postoperative pathological results were then analyzed.A comparison was made between the benign and malignant nodule groups,including the basic condition of patients(age,gender,smoking history,drinking history,diabetes mellitus,fasting blood glucose before ¹⁸F-FDG PET/CT examination,BMI),maximum diameter of nodules,morphological characteristics of nodules（lobulation sign,vacuole sign,spiculation,pleural traction,vascular convergence sign）,SUVmax and CTR.The correlation between the maximum diameter of nodules,the morphological characteristics of nodules,SUVmax,CTR and the nature of small pulmonary nodules was analyzed to determine the optimal diagnostic cut-off value for statistically significant results and to analyze their diagnostic efficacy.Results:The ¹⁸F-FDG PET/CT’s sensitivity,specificity,accuracy,positive predictive value and negative predictive value in diagnosing small pulmonary nodules were 71.84%,66.67%,70.5%,86.04%and 45.28%,respectively.No statistically significant correlations were found between the basic condition of patients,maximum diameter of nodules,morphological characteristics of nodules,CTR and consistency of diagnosis（P>0.05）,however SUVmax was positively correlated with diagnostic consistency and was statistically significant,P<0.05（P=0.001）;There were no significant differences in the basic condition of patients,maximum diameter of nodules,morphological characteristics of nodules（lobulation sign,vacuole sign,spiculation,pleural traction）and CTR between the benign and malignant nodules groups（P>0.05）.Vascular convergence sign and SUVmax were significantly different between benign and malignant groups,P<0.05(P_血=0.028,P_SUV=0.000).There was no significant correlation between the maximum diameter of nodules,the morphological characteristics of nodules),CTR and the ature of small pulmonary nodules（P>0.05）.SUVmax was positively correlated with the nature of small pulmonary nodules,P<0.05（P=0.000）and the optimal diagnostic cut-off value of SUVmax was further determined to be 0.05,with a corresponding sensitivity of 87.50%（42/48）,specificity of 51.64%（47/91）,accuracy of 64.03%（89/139）,positive predictive value of 48.63%（42/86）,and negative predictive value of88.67%（47/53）.Conclusion:1.¹⁸F-FDG PET/CT has good sensitivity,accuracy and positive predictive value in the diagnosis of benign and malignant small pulmonary nodules.2.The presence of vascular convergence sign in ¹⁸F-FDG PET/CT images is diagnostic for the determination of benign and malignant small pulmonary nodules.3.SUVmax was correlated with the diagnostic consistency of ¹⁸F-FDG PET/CT and postoperative pathological results,and the greater SUVmax,the higher the diagnostic consistency.4.SUVmax has diagnostic significance for benign and malignant small pulmonary nodules,and SUVmax=0.05 is defined as the optimal diagnostic cut-off value,with high sensitivity and negative predictive value.